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OS Memory Usage   «Prev  Next»
Lesson 1

Tuning for OS memory usage

Tuning Oracle memory

Another very important component of the external environment when tuning Oracle system is the memory consumption within your Oracle database server. Many DBAs falsely assume that the only memory they need to worry about is the memory that is allocated to their SGA when they create the Oracle instance. However the savvy DBA understands that there are additional memory demands upon the database server even one that is totally dedicated to the Oracle database. We have to deal with the demands of PGA memory for all of the connected users as well as dealing with memory demands for other components of the Oracle database, including the database listener, multithreaded server, and all of the other components that are running within your database server environment. In this module were going to be looking at the generic tool called vmstat that will actually measured the amount of paging and swapping all OS memory within your Oracle instance.

Managing RAM memory

In this module, you will delve into managing the RAM memory in the OS environment.
Memory has a huge impact on performance. Because of this, Oracle allocates a region of RAM memory, called the SGA, at database startup time. Each connected user process causes the database server to experience Oracle-related memory demands. Therefore, you must understand a range of memory management techniques. By the end of this module, you should be able to:
  1. Explain virtual memory
  2. Explain UNIX memory management
  3. Check the vmstat run queue
  4. Place statistics into Oracle tables
  5. Reduce memory usage
The next lesson is an overview of OS memory usage.